I have a 1997 Venture 600 twin that I just picked up. It has only 5000 miles on it and is perfect shape. I had to do some things considering it sat for 9 years and never started. Getting the bugs out, but there is one that I need some help with. That is it tach’s out at 6800. The specs call for a shift speed of 7800. I removed the primary clutch and discovered that the rollers were worn considerably, and have just installed 3 new ones. That did make a difference for sure. As opposed to the first run when it was shifting very weirdly. I painted the sheave on the primary face and after running full throttle, stopped and observed that the belt is 1” below the top of the sheave. So obviously the engine is too slow and not driving the belt all the way up. After installing the new rollers found it does not to run past 6800 WOT. Smooth as can be, carbs are completely clean, plugs looked good.
so I thought, “wonder what the compression is?”. They are 92psi left side, 100psi right side.
Does anyone know what it should be? Is this real low? Would this seen compression be too low to make full RPM?
so I thought, “wonder what the compression is?”. They are 92psi left side, 100psi right side.
Does anyone know what it should be? Is this real low? Would this seen compression be too low to make full RPM?
That compression reading is a bit low, but those engines have a very thick head gasket from the factory.
What you really want to watch, is the difference between the 2 cylinders, and yours looks to be OK.
What you really want to watch, is the difference between the 2 cylinders, and yours looks to be OK.
Update. Just took the weights out and there is 8AY weights installed, plus a solid steel rivet. There is only one hole in the weight. According to the stock chart, there should be 8cr installed with, 10.3/17.3 in the two holes. Deducing the 10.3 and 17.2 that is mm. And there are two weights associated with the 17.2 mm rivet. One is steel, and the other steel with a hole. The solid one is 4.5 grams, the other 3.6 grams. I weighed the install 8ay with rivet, and that is 61.1g total. Does any one know what the weight of a stock 8cr weight is? Guessing what is installed is too heavy, thus low RPM.
Someone must have installed a different clutch on this sled as why else would it be different. BTW: the previous owner bought it new, and is in his 80’s, cant imagine why he’d frig with It.
Someone must have installed a different clutch on this sled as why else would it be different. BTW: the previous owner bought it new, and is in his 80’s, cant imagine why he’d frig with It.
and you have found your problem!
If its 8AY weights, those are out of a pogo style Vmax sled.
If it were me, I would gather up the factory stuff, springs, rollers, weights and rivets, even helix.
Once you have that stuff intstalled, it will work as intended.
You can make what you have work, but will take a bit of trial and error, swapping of rivets, springs, ect.
Easier to do the stock stuff IMO.
If its 8AY weights, those are out of a pogo style Vmax sled.
If it were me, I would gather up the factory stuff, springs, rollers, weights and rivets, even helix.
Once you have that stuff intstalled, it will work as intended.
You can make what you have work, but will take a bit of trial and error, swapping of rivets, springs, ect.
Easier to do the stock stuff IMO.
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The belt will never run to the top of the primary clutch sheaves in a stock Yamaha primary clutch unless it has been modified for over drive.
Full shift out on a stock primary brings the belt just over 1/2" from the top of the sheaves.
Full shift out on a stock primary brings the belt just over 1/2" from the top of the sheaves.
there was a few twin clutch set ups for the xtc twins in the tec pages as that era, the clutching was not that great. might be able to find some of that stuff easyier than the stock stuff.
I think the 8AY were used in late Exciters.
How's the surface of the weights?
How's the surface of the weights?
Check all engine mounts also. I've seen the bolts back out or break off on the left front, where they bolt into the crankcase.
In addition, it's very important to inspect and lubricate the oil pump drive on these engines yearly.
In addition, it's very important to inspect and lubricate the oil pump drive on these engines yearly.
The surface of the weights are smooth, no ridges. Thanks for the tip about lubricating the oil pump drive